The study by Italy's Monza and Brianza Chamber of Commerce based its findings on a monument's “image, brand and visibility”, calculated by cross-referencing 10 different parameters from various analysts and statistics bodies.

Criteria included a “tourist index”, which took into account “the economic value of the location, the fame of the monument, the flux of visitors to the territory and monument” and an “economic attractiveness index”, comprising factors such as the number of jobs it created and its export value.

The huge value of the “Iron Lady” – as the 1,050ft tall edifice is affectionately known, amounts to almost a fifth of France's entire annual gross domestic product, Le Figaro pointed out.

The Italian media was horrified by the news that the Paris landmark was said to be worth twice as much as the annual wealth generated by the entire city of Milan.

Il giornale website asked: “Is the Eiffel Tower really worth that much? And above all, are we sure it’s worth more than the Colusseum and Duomo combined?

“If the answer is no, the logical conclusion is that in Italy we don’t know how to make as much as we should out of the vast artistic and cultural heritage we possess.”

The country's Panorama news magazine was equally hand-wringing: “Is this is a surprising, outrageous and incredible assessment? Not really. It forces us to face the harsh reality of a country that has lost its memory.”

Built in 1889, the Eiffel Tower is Europe's most visited monument, attracting almost eight million tourists a year.